You might want to scroll two threads down. Just poured some high temp silicon into my molds, it worked out but I needed a few attempts and had to fix them to the mold with superglue. I could post a pic but it would look no different (maybe a bit more sloppy) from Crappiehappy`s posting there.
All i can add is - with the second half, don´t rely on talcum powder, less is more and rather use celuphane foil. Also, mind the bubbles, start pouring at the edge that is closest to the lead head and then insert the colarless jig and pour some more.
Good luck!